1. Field of the Invention
This invention relates to apparatuses for photographing pipeline interiors, and more particularly, self-navigated apparatuses for recording images of pipeline interiors.
2. Description of Related Art
Municipalities and utilities often have very long underwater pipelines to maintain. Often, there are blockages created by debris, and particularly in the Great Lakes, accumulations of mussels on the pipeline interior walls. To determine what measures are necessary to maintain the pipeline, it is necessary to see the pipeline interior. In some cases, a diver may swim into the pipeline carrying a camera. This is a very dangerous operation and there are very few divers who will attempt it. In many cases, pipelines are too long for a diver to swim.
Some efforts have been made to develop robotic devices for photographing pipeline interiors. Typically, these devices are tethered to a winch or are motor-driven. The tethered devices are limited by the length of the tether, the longest of which is about two miles. Some pipelines are several miles in length which is too long for conventional tethered devices. Motor-driven divices are limited by their battery life. These devices use power-consuming motors, complex control systems, numerous parts, and are costly. Thus, there is a great need for a simple, inexpensive device for photographing pipeline interiors which is capable of operating over long distances.